On-chip integration of InGaAs/GaAs quantum dot lasers with waveguides and modulators on silicon

Abstract

Compound-semiconductor-based photonic devices, including lasers and modulators, directly grown and on-chip integrated on Si substrates provide a promising approach for the realization of optical interconnects with CMOS compatibility. Utilizing quantum dots as efficient dislocation filters near the GaAs-Si interface, for the first time, we demonstrated high-performance InGaAs/GaAs quantum dot (QD) lasers on silicon with a relatively low threshold current density (J, h = 900 A/cm 2 ), large small-signal modulation bandwidth of 5.5 GHz, and a high characteristic temperature (T 0 = 278 K). The integrated InGaAs QD lasers with quantum well (QW) electroabsorption modulators, achieved through molecular beam epitaxy (MBE) growth and regrowth, exhibit a coupling coefficient greater than 20% and a modulation depth ∼100% at 5 V reverse bias. We achieved the monolithic integration of amorphous and crystalline silicon waveguides with quantum dot lasers by using plasma-enhanced-chemical-vapor deposition (PECVD) and membrane transfer, respectively. Finally, preliminary results on the integration of QD lasers with Si CMOS transistors are presented.